1. Field of the Invention
The invention relates in general to a group antenna comprising a plurality of line-fed individual radiators with omni-directional characteristics distributed within the volume of an imaginary body particularly a sphere which is symmetrical with respect to one horizontal plane and two intersecting vertical planes with the group antenna comprising electronically phasecontrolled beams for all-around radar scanning.
2. Description of the Prior Art
A group antenna is known from German patent No. 28 22 845.However, a precise target locating or, respectively, target tracking is not possible with this antenna.
In order to enable a precise target locating or target tracking with a group antenna, the mono-pulse method with a sum diagram and corresponding different diagrams is usually employed. For this purpose, a division of the individual radiators into subgroups and into a suitable combination is necessary.
Mono-pulse antennas which have previously been employed correspond to a planar rather than a three-dimensional element arrangement wherein the four sub-surfaces or sub-antennas are combined in a sum-channel and an elevation difference channel and an azimuth different channel.